Most email issues? User error—about 90–95% in my experience. Instead of sending the same questions over and over, I made a quick checklist to help spot common problems fast:
Are you connected to the internet?
Can you access webmail?
Are your username/password correct?
Are your settings (IMAP/SMTP) entered correctly?
Any full inbox or quota issues?
Are there any error messages?
Is your antivirus/firewall blocking email?
I might expand on each later, but this list catches most problems.
—Jessica Dunbar